System and method for varying response amplitude of radio transponders
First Claim
1. A method for locating an object using a radio frequency identification system, the method comprising:
- communicating at least one interrogation signal to a chip-based radio frequency identification tag comprising an antenna and a chip in communication with the antenna;
transmitting at least one response signal from the radio frequency identification tag to each one of a plurality of radio frequency identification readers;
reducing an effective reading range of the transmitted response signal over time by controlling the amplitude of backwater radiation that the radio frequency identification tag, uses to communicate with the radio frequency identification readers;
identifying a minimum effective reading range of the transmitted response signal for each one of the plurality of radio frequency identification readers; and
determining a location of the radio frequency identification tag based upon the identified minimum effective reading ranges.
1 Assignment
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Accused Products
Abstract
A system and method are provided for modifying the effective reading range of an radio frequency identification tag. The tag, a chip based tag, includes an antenna and a chip in communication with the antenna. The chip includes circuitry including field effect transistors that can modify the effective reading range of the tag by modifying characteristics of the tag including the modulation depth of the backscatter signal, the impedance characteristics of the tag front end electronics, the power consumption characteristics and the threshold power-on voltage of the tag. These characteristics are change either temporarily or permanently in response to commands communicated to the tag from a radio frequency identification reader.
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Citations
11 Claims
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1. A method for locating an object using a radio frequency identification system, the method comprising:
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communicating at least one interrogation signal to a chip-based radio frequency identification tag comprising an antenna and a chip in communication with the antenna; transmitting at least one response signal from the radio frequency identification tag to each one of a plurality of radio frequency identification readers; reducing an effective reading range of the transmitted response signal over time by controlling the amplitude of backwater radiation that the radio frequency identification tag, uses to communicate with the radio frequency identification readers; identifying a minimum effective reading range of the transmitted response signal for each one of the plurality of radio frequency identification readers; and determining a location of the radio frequency identification tag based upon the identified minimum effective reading ranges. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification